Applied Mechanics and Materials Vols. 166-169

Abstract: A medium speed mill-foundation coupled finite element model was established using ANSYS. The modal and harmonic responses of medium-speed mill were analyzed. The influence of the number of vibration isolators and the ratio of foundation bedplate to equipment on the vibration of mill was analyzed. The shock absorption measures of medium-speed mills were discussed. To get good vibration isolation effect, the maximum horizontal vibration displacement of medium-speed mill with spring vibration-isolated foundation is suggested as 50 μm, and the ratio of foundation bedplate to equipment as 3.0±0.2.

Abstract: Finite element analysis method of steel reinforced lightweight concrete pull-out specimens is exploded based on the test results. Spring element and local bond slip constitutive relation are introduced in analysis so as to consider the interfacial bond-slip between steel and lightweight concrete. Element tributary area and flange or web position should be taken into account in order to confirm the spring element real constant. Analysis results indicate that specimens bearing capacity and deformation can be well simulated adopting the stated method and constitutive relationship.

Abstract: Nonlinear analysis of plate and shell structures can explain the phenomenon which cannot been explained by classical stability theory, and can obtain better validation of experimental results. Stability problems are essentially nonlinear and their nonlinear finite element solutions ultimately result in solving nonlinear algebraic equations and nonlinear eigenvalue problems. The solutions can define the shape of basic path and determine critical load by using the incremental method, The perturbation methods are used near the critical point, and the basic formulas are given for initial post-buckling analysis by FEM.

Abstract: Technical Code for Design of Cold-formed Thin-wall Steel Structures mainly provides single-limb and lattice sections of axially-loaded members of cold-formed thin-walled steel, and there is no related design method for compound section. In this paper, combined the relevant test datas, the load-carrying performance of short axially-loaded column with gusset plate between double cold-formed C steel were analyzed through effective width method from code and DSM. By comparing the computing results with test results, it indicates that the computing results of DSM are more consistent with the test datas. As a result, I come up with suggestion formulas of effective width method which are applied to short axially-loaded column with gusset plate between double cold-formed thin-walled C steel.

Abstract: To evaluate the vibration performance of medium-speed mill-foundation coupled system, eight mills in five thermal power plants were tested in site. The vibration displacement and acceleration of upper and lower bedplates of foundations and equipment bodies were measured. According to the test results, the vibration safety of mills is evaluated. The study shows that the vibration displacement of medium-speed mill with spring vibration-isolated foundation meets the code requirements, but the vibration displacement of equipment body is larger. The vibration displacement of equipment body should be controlled by limiting the vibration displacement of foundation platform in design.

Abstract: In order to study and solve the problem of connection on the part of the prestressed tendons RPC concrete pole engineering. Design connecting flange suitable for the existing part of the prestressed tendons RPC concrete pole developed by our group used the connection flange in Steel tower as the prototype.Through the ABAQUS software to establish the finite element model between the connection flange and part of the prestressed tendons RPC concrete pole, and carry out finite element analysis.Through the finite element analysis to get results whether the design of connecting flange can meet the strength requirements when the prestressed tendons RPC concrete pole is under ultimate load, so to get the practical design method of the 500kv part prestressed RPC concrete pole connecting flange.

Abstract: Through exposure test of FRP-reinforced concrete member in littoral test area of temperate marine zone, the durability and constructional measures of FRP-reinforced concrete structure are investigated. The test results show that FRP shell on the surface of FRP-reinforced concrete member is effective in avoiding wave flush, freezing and thawing damage, preventing chloride ion corrosion and improving durability. On the other hand, reliable measures should be taken to protect concrete structures with no FRP shell on the surface. Based on above, the provided reference for evaluation durability of FRP-reinforced concrete structure, and proper constructional measures for FRP-reinforced concrete structure are presented.

Abstract: Based on the characteristics of 3D parking, a new type of 3D parking structure with alternation story-height truss lateral-load-resisting system is proposed in this paper. By adoption of the assumption of inflection point, a simplified analytical method for this system under horizontal load is studied and the formulas for internal forces of it are derived. The numerical example indicates that the error of the results calculated by the presented formulas does not exceed 5% in comparison with those by finite element method. Therefore, the method and its related formulas are feasible for preliminary design of the steel 3D parking structure since its accuracy and briefness.

Abstract: Structure optimization seeks to achieve the best performance for a structure while satisfying various constrains such as a given probability. In the traditional mathematical model of structure optimization, the goal and the restraint functions are given without considering the randomness of the structural system. In this paper, the random loads and strength are described by probability method, the structure reliability is considered as objective function. Using the genetic algorithm, the mega-sub controlled structural systems is multi-objective optimization designed based on the structure reliability under random excitation, combined with the probability density evolution method for evaluation of extreme value distribution. A low-cost and high-performance structure is getting.

Abstract: Six latticed concrete-filled steel tubular (CFST) wind turbine tower K-shape joints were carried on the static load test, which included the weld intersecting joint and gusset plate joint. The failure mechanism and characteristics on the two kinds of K-shape joints, the deformation development process after joints entered plastic stage and the stress state and distribution of joint intersection area were studied. The results show that the failure mode and mechanical behavior of CFST K-shape joints are greatly different from that of the hollow steel tube K-shape joints because of the existence of core concrete, the failure mode of the weld intersecting joints showed the local buckling of compression web member and that of the gusset plate joints presented as the compression buckling and tension tearing of the gusset plates, while the plastic deformation failure of tower column tube wall in joint area was not appear. It is also shown by test results that the stress distribution of tower column tube wall and gusset plate in joint intersection is extremely non-uniform, individual parts already enter plastic state but some other parts are still in elastic state. According to the failure mode and stress distribution conditions of the two kinds of K-shape joints, some design suggestions are drawn, which can provide reference for the latticed CFST wind turbine tower joints.